Response properties of upper cervical spinothalamic neurons in cats. A possible explanation for the unusual sensory symptoms associated with upper cervical lesions in humans.

Abstract

Lesions in the foramen magnum and upper cervical spinal cord often cause an unusual array of sensory changes and atrophic weakness, primarily involving the ipsilateral forelimb. Furthermore, small midline myelotomies performed at C1 often lead to widespread analgesia covering most of the body in patients with chronic pain. These observations challenge physicians' understanding of anatomy and physiology in the upper cervical region. Using single cell recording techniques the authors have shown that spinothalamic neurons in the second cervical segment of cats have complex response properties, often responding to stimuli throughout the body. These findings together with a review of clinical and basic science literature are used to provide explanations for the unusual signs and symptoms observed in patients with upper cervical and foramen magnum lesions.